Technical Field
[0001] The present invention relates to a stacking-type header, a heat exchanger, and an
air-conditioning apparatus.
Background Art
[0002] As a related-art stacking-type header, there is known a stacking-type header including
a first plate-shaped unit having formed therein a plurality of outlet flow passages
and a plurality of inlet flow passages, and a second plate-shaped unit stacked on
the first plate-shaped unit and having formed therein an inlet flow passage communicating
with the plurality of outlet flow passages formed in the first plate-shaped unit,
and an outlet flow passage communicating with the plurality of inlet flow passages
formed in the first plate-shaped unit (for example, see Patent Literature 1).
Citation List
Patent Literature
[0003] Patent Literature 1: Japanese Unexamined Patent Application Publication No.
2000-161818 (paragraph [0032] to paragraph [0036], Fig. 7 & Fig. 8)
Summary of Invention
Technical Problem
[0004] In such a stacking-type header, for example, when superheated refrigerant flows
into a part between the plurality of inlet flow passages of the first plate-shaped
unit and the outlet flow passage of the second plate-shaped unit, the superheated
refrigerant exchanges heat with low-temperature refrigerant flowing through a part
between the plurality of outlet flow passages of the first plate-shaped unit and the
inlet flow passage of the second plate-shaped unit. In other words, the related-art
stacking-type header has a problem in that the heat exchange loss of the refrigerant
is large.
[0005] The present invention has been made in view of the above-mentioned problem, and has
an object to provide a stacking-type header reduced in heat exchange loss of refrigerant.
Further, the present invention has an object to provide a heat exchanger including
such a stacking-type header. Further, the present invention has an object to provide
an air-conditioning apparatus including such a heat exchanger.
Solution to Problem
[0006] According to one embodiment of the present invention, there is provided a stacking-type
header, including: a first plate-shaped unit having formed therein a plurality of
first outlet flow passages and a plurality of first inlet flow passages; and a second
plate-shaped unit stacked on the first plate-shaped unit, the second plate-shaped
unit having formed therein: at least a part of a distribution flow passage configured
to distribute refrigerant, which passes through a second inlet flow passage to flow
into the second plate-shaped unit, to the plurality of first outlet flow passages
to cause the refrigerant to flow out from the second plate-shaped unit; and at least
a part of a joining flow passage configured to join together flows of the refrigerant,
which pass through the plurality of first inlet flow passages to flow into the second
plate-shaped unit, to cause the refrigerant to flow out toward a second outlet flow
passage, in which the first plate-shaped unit or the second plate-shaped unit includes
at least one plate-shaped member having formed therein: a flow passage through which
the refrigerant passes to flow into the plurality of first inlet flow passages; and
a flow passage through which the refrigerant passes to flow into the second inlet
flow passage, and in which the at least one plate-shaped member has a through portion
or a concave portion formed in at least a part of a region between the flow passage
through which the refrigerant passes to flow into the plurality of first inlet flow
passages and the flow passage through which the refrigerant passes to flow into the
second inlet flow passage.
Advantageous Effects of Invention
[0007] In the stacking-type header according to the one embodiment of the present invention,
the first plate-shaped unit or the second plate-shaped unit includes the at least
one plate-shaped member having formed therein: the flow passage through which the
refrigerant passes to flow into the first inlet flow passages; and the flow passage
through which the refrigerant passes to flow into the second inlet flow passage. The
through portion or the concave portion is formed in the plate-shaped member in at
least a part of the region between the flow passage through which the refrigerant
passes to flow into the first inlet flow passages and the flow passage through which
the refrigerant passes to flow into the second inlet flow passage. Therefore, it is
possible to suppress the heat exchange loss of the refrigerant.
Brief Description of Drawings
[0008]
[Fig. 1] Fig. 1 is a view illustrating a configuration of a heat exchanger according
to Embodiment 1.
[Fig. 2] Fig. 2 is a perspective view illustrating the heat exchanger according to
Embodiment 1 under a state in which a stacking-type header is disassembled.
[Fig. 3] Fig. 3 is a developed view of the stacking-type header of the heat exchanger
according to Embodiment 1.
[Fig. 4] Fig. 4 is a diagram illustrating a configuration of an air-conditioning apparatus
to which the heat exchanger according to Embodiment 1 is applied.
[Fig. 5] Fig. 5 is a view illustrating first heat insulating slits formed in a third
plate-shaped member of Modified Example-1 of the heat exchanger according to Embodiment
1.
[Fig. 6] Fig. 6 is a perspective view of Modified Example-2 of the heat exchanger
according to Embodiment 1 under a state in which the stacking-type header is disassembled.
[Fig. 7] Fig. 7 is a perspective view of Modified Example-3 of the heat exchanger
according to Embodiment 1 under a state in which the stacking-type header is disassembled.
[Figs. 8] Figs. 8 are a main-part perspective view and a main-part sectional view
of Modified Example-4 of the heat exchanger according to Embodiment 1 under a state
in which the stacking-type header is disassembled.
[Fig. 9] Fig. 9 is a perspective view of Modified Example-5 of the heat exchanger
according to Embodiment 1 under a state in which the stacking-type header is disassembled.
[Fig. 10] Fig. 10 is a perspective view of Modified Example-6 of the heat exchanger
according to Embodiment 1 under a state in which the stacking-type header is disassembled.
[Fig. 11] Fig. 11 is a view illustrating a configuration of a heat exchanger according
to Embodiment 2.
[Fig. 12] Fig. 12 is a perspective view illustrating the heat exchanger according
to Embodiment 2 under a state in which a stacking-type header is disassembled.
[Figs. 13] Figs 13 are a developed view of the stacking-type header of the heat exchanger
according to Embodiment 2.
[Fig. 14] Fig. 14 is a diagram illustrating a configuration of an air-conditioning
apparatus to which the heat exchanger according to Embodiment 2 is applied.
Description of Embodiments
[0009] Now, a stacking-type header according to the present invention is described with
reference to the drawings.
[0010] Note that, in the following, there is described a case where the stacking-type header
according to the present invention distributes refrigerant flowing into a heat exchanger,
but the stacking-type header according to the present invention may distribute refrigerant
flowing into other devices. Further, the configuration, operation, and other matters
described below are merely examples, and the present invention is not limited to such
configuration, operation, and other matters. Further, in the drawings, the same or
similar components are denoted by the same reference symbols, or the reference symbols
therefor are omitted. Further, the illustration of details in the structure is appropriately
simplified or omitted. Further, overlapping description or similar description is
appropriately simplified or omitted.
Embodiment 1
[0011] A heat exchanger according to Embodiment 1 is described.
<Configuration of Heat Exchanger>
[0012] Now, the configuration of the heat exchanger according to Embodiment 1 is described.
[0013] Fig. 1 is a view illustrating the configuration of the heat exchanger according to
Embodiment 1.
[0014] As illustrated in Fig. 1, a heat exchanger 1 includes a stacking-type header 2, a
plurality of first heat transfer tubes 3, a retaining member 4, and a plurality of
fins 5.
[0015] The stacking-type header 2 includes a refrigerant inflow port 2A, a plurality of
refrigerant outflow ports 2B, a plurality of refrigerant inflow ports 2C, and a refrigerant
outflow port 2D. Refrigerant pipes are connected to the refrigerant inflow port 2A
of the stacking-type header 2 and the refrigerant outflow port 2D of the stacking-type
header 2. The first heat transfer tube 3 is a flat tube subjected to hair-pin bending.
The plurality of first heat transfer tubes 3 are connected between the plurality of
refrigerant outflow ports 2B of the stacking-type header 2 and the plurality of refrigerant
inflow ports 2C of the stacking-type header 2.
[0016] The first heat transfer tube 3 is a flat tube having a plurality of flow passages
formed therein. The first heat transfer tube 3 is made of, for example, aluminum.
Both ends of the plurality of first heat transfer tubes 3 are connected to the plurality
of refrigerant outflow ports 2B and the plurality of refrigerant inflow ports 2C of
the stacking-type header 2 under a state in which both the ends are retained by the
plate-shaped retaining member 4. The retaining member 4 is made of, for example, aluminum.
The plurality of fins 5 are joined to the first heat transfer tubes 3. The fin 5 is
made of, for example, aluminum. It is preferred that the first heat transfer tubes
3 and the fins 5 be joined by brazing. Note that, in Fig. 1, there is illustrated
a case where eight first heat transfer tubes 3 are provided, but the present invention
is not limited to such a case.
<Flow of Refrigerant in Heat Exchanger>
[0017] Now, the flow of the refrigerant in the heat exchanger according to Embodiment 1
is described.
[0018] The refrigerant flowing through the refrigerant pipe passes through the refrigerant
inflow port 2A to flow into the stacking-type header 2 to be distributed, and then
passes through the plurality of refrigerant outflow ports 2B to flow out toward the
plurality of first heat transfer tubes 3. In the plurality of first heat transfer
tubes 3, the refrigerant exchanges heat with air supplied by a fan, for example. The
refrigerant flowing through the plurality of first heat transfer tubes 3 passes through
the plurality of refrigerant inflow ports 2C to flow into the stacking-type header
2 to be joined, and then passes through the refrigerant outflow port 2D to flow out
toward the refrigerant pipe. The refrigerant can reversely flow.
<Configuration of Laminated Header>
[0019] Now, the configuration of the stacking-type header of the heat exchanger according
to Embodiment 1 is described.
[0020] Fig. 2 is a perspective view illustrating the heat exchanger according to Embodiment
1 under a state in which the stacking-type header is disassembled. Fig. 3 is a developed
view of the stacking-type header of the heat exchanger according to Embodiment 1.
Note that, in Fig. 2, the illustration of a first heat insulating slit 31 is omitted.
Further, in Fig. 3, the illustration of a both-side clad member 24 is omitted.
[0021] As illustrated in Fig. 2 and Fig. 3, the stacking-type header 2 includes a first
plate-shaped unit 11 and a second plate-shaped unit 12. The first plate-shaped unit
11 and the second plate-shaped unit 12 are stacked on each other.
[0022] The first plate-shaped unit 11 is stacked on the refrigerant outflow side. The first
plate-shaped unit 11 includes a first plate-shaped member 21. The first plate-shaped
unit 11 has formed therein a plurality of first outlet flow passages 11A and a plurality
of first inlet flow passage 11 B. The plurality of first outlet flow passages 11A
correspond to the plurality of refrigerant outflow ports 2B in Fig. 1. The plurality
of first inlet flow passages 11 B correspond to the plurality of refrigerant inflow
ports 2C in Fig. 1.
[0023] The first plate-shaped member 21 has formed therein a plurality of flow passages
21A and a plurality of flow passages 21 B. The plurality of flow passages 21A and
the plurality of flow passages 21 B are each a through hole having an inner peripheral
surface shaped conforming to an outer peripheral surface of the first heat transfer
tube 3. When the first plate-shaped member 21 is stacked, the plurality of flow passages
21A function as the plurality of first outlet flow passages 11A, and the plurality
of flow passages 21 B function as the plurality of first inlet flow passages 11 B.
The first plate-shaped member 21 has a thickness of about 1 mm to 10 mm, and is made
of aluminum, for example. When the plurality of flow passages 21A and 21 B are formed
by press working or other processing, the work is simplified, and the manufacturing
cost is reduced.
[0024] The second plate-shaped unit 12 is stacked on the refrigerant inflow side. The second
plate-shaped unit 12 includes a second plate-shaped member 22 and a plurality of third
plate-shaped members 23_1 to 23_3. The second plate-shaped unit 12 has formed therein
a second inlet flow passage 12A, a distribution flow passage 12B, a joining flow passage
12C, and a second outlet flow passage 12D. The distribution flow passage 12B includes
a plurality of branching flow passages 12b. The joining flow passage 12C includes
a mixing flow passage 12c. The second inlet flow passage 12A corresponds to the refrigerant
inflow port 2A in Fig. 1. The second outlet flow passage 12D corresponds to the refrigerant
outflow port 2D in Fig. 1.
[0025] Note that, a part of the distribution flow passage 12B or a part of the joining flow
passage 12C may be formed in the first plate-shaped unit 11. In such a case, a flow
passage may be formed in the first plate-shaped member 21, the second plate-shaped
members 22, the plurality of third plate-shaped members 23_1 to 23_3, or other members,
for turning back the refrigerant flowing therein to cause the refrigerant to flow
out therefrom. When the flow passage for turning back the refrigerant flowing therein
to cause the refrigerant to flow out therefrom is not formed, and the whole distribution
flow passage 12B or the whole joining flow passage 12C is formed in the second plate-shaped
unit 12, a width dimension of the stacking-type header 2 can be substantially equal
to a width dimension of the first heat transfer tube 3, which achieves compactification
of the heat exchanger 1.
[0026] The second plate-shaped member 22 has a flow passage 22A and a flow passage 22B formed
therein. The flow passage 22A and the flow passage 22B are each a circular through
hole. When the second plate-shaped member 22 is stacked, the flow passage 22A functions
as the second inlet flow passage 12A and the flow passage 22B functions as the second
outlet flow passage 12D. The second plate-shaped member 22 has a thickness of about
1 mm to 10 mm, and is made of aluminum, for example. When the flow passage 22A and
the flow passage 22B are each formed by press working or other processing, the work
is simplified, and the manufacturing cost and the like are reduced.
[0027] For example, fittings or other such components are provided on the surface of the
second plate-shaped member 22 on the side on which other members are not stacked,
and the refrigerant pipes are connected to the second inlet flow passage 12A and the
second outlet flow passage 12D through the fittings or other such components, respectively.
The inner peripheral surfaces of the second inlet flow passage 12A and the second
outlet flow passage 12D may be shaped to be fitted to the outer peripheral surfaces
of the refrigerant pipes so that the refrigerant pipes may be directly connected to
the second inlet flow passage 12A and the second outlet flow passage 12D without using
the fittings or other such components. In such a case, the component cost and the
like are reduced.
[0028] The plurality of third plate-shaped members 23_1 to 23_3 respectively have a plurality
of flow passages 23A_1 to 23A_3 formed therein. The plurality of flow passages 23A_1
to 23A_3 are each a through groove having two end portions 23a and 23b. When the plurality
of third plate-shaped members 23_1 to 23_3 are stacked, each of the plurality of flow
passages 23A_1 to 23A_3 functions as the branching flow passage 12b. The plurality
of third plate-shaped members 23_1 to 23_3 each have a thickness of about 1 mm to
10 mm, and are made of aluminum, for example. When the plurality of flow passages
23A_1 to 23A_3 are formed by press working or other processing, the work is simplified,
and the manufacturing cost and the like are reduced.
[0029] Further, the plurality of third plate-shaped members 23_1 to 23_3 respectively have
a plurality of flow passages 23B_1 to 23B_3 formed therein. The plurality of flow
passages 23B_1 to 23B_3 are each a rectangular through hole passing through substantially
the entire region in the height direction of each of the third plate-shaped members
23_1 to 23_3. When the plurality of third plate-shaped members 23_1 to 23_3 are stacked,
each of the plurality of flow passages 23B_1 to 23B_3 functions as a part of the mixing
flow passage 12c. The plurality of flow passages 23B_1 to 23B_3 may not have a rectangular
shape.
[0030] In the following, in some cases, the plurality of third plate-shaped members 23_1
to 23_3 are collectively referred to as the third plate-shaped member 23. In the following,
in some cases, the plurality of flow passages 23A_1 to 23A_3 are collectively referred
to as the flow passage 23A. In the following, in some cases, the plurality of flow
passages 23B_1 to 23B_3 are collectively referred to as the flow passage 23B. In the
following, in some cases, the retaining member 4, the first plate-shaped member 21,
the second plate-shaped member 22, and the third plate-shaped member 23 are collectively
referred to as the plate-shaped member.
[0031] The flow passage 23A formed in the third plate-shaped member 23 has a shape in which
the two end portions 23a and 23b are connected to each other through a straight-line
part 23c perpendicular to the gravity direction. The branching flow passage 12b is
formed by closing, by a member stacked adjacent on the refrigerant inflow side, the
flow passage 23A in a region other than a partial region 23d (hereinafter referred
to as "opening port 23d") between both ends of the straight-line part 23c, and closing,
by a member stacked adjacent on the refrigerant outflow side, the flow passage 23A
in a region other than the end portion 23a and the end portion 23b.
[0032] In order to branch the refrigerant flowing into the flow passage to have different
heights and cause the refrigerant to flow out therefrom, the end portion 23a and the
end portion 23b are positioned at heights different from each other. In particular,
when one of the end portion 23a and the end portion 23b is positioned on the upper
side relative to the straight-line part 23c, and the other thereof is positioned on
the lower side relative to the straight-line part 23c, each distance from the opening
port 23d along the flow passage 23A to each of the end portion 23a and the end portion
23b can be less biased without complicating the shape. When the straight line connecting
between the end portion 23a and the end portion 23b is set parallel to the longitudinal
direction of the third plate-shaped member 23, the dimension of the third plate-shaped
member 23 in the transverse direction can be decreased, which reduces the component
cost, the weight, and the like. Further, when the straight line connecting between
the end portion 23a and the end portion 23b is set parallel to the array direction
of the first heat transfer tubes 3, space saving can be achieved in the heat exchanger
1.
[0033] The branching flow passage 12b branches the refrigerant flowing therein into two
flows to cause the refrigerant to flow out therefrom. Therefore, when the number of
the first heat transfer tubes 3 to be connected is eight, at least three third plate-shaped
members 23 are required. When the number of the first heat transfer tubes 3 to be
connected is sixteen, at least four third plate-shaped members 23 are required. The
number of the first heat transfer tubes 3 to be connected is not limited to powers
of 2. In such a case, the branching flow passage 12b and a non-branching flow passage
may be combined with each other. Note that, the number of the first heat transfer
tubes 3 to be connected may be two.
[0034] Note that, the stacking-type header 2 is not limited to a stacking-type header in
which the plurality of first outlet flow passages 11A and the plurality of first inlet
flow passage 11 B are arrayed along the gravity direction, and may be used in a case
where the heat exchanger 1 is installed in an inclined manner, such as a heat exchanger
for a wall-mounting type room air-conditioning apparatus indoor unit, an outdoor unit
for an air-conditioning apparatus, or a chiller outdoor unit. In such a case, the
straight-line part 23c may be formed as a through groove shaped so that the straight-line
part 23c is not perpendicular to the longitudinal direction of the third plate-shaped
member 23.
[0035] Further, the flow passage 23A may have a different shape. For example, the flow passage
23A may not have the straight-line part 23c. In such a case, a horizontal part between
the end portion 23a and the end portion 23b of the flow passage 23A, which is substantially
perpendicular to the gravity direction, serves as the opening port 23d. In a case
where the flow passage 23A has the straight-line part 23c, the influence of the gravity
is reduced when the refrigerant is branched at the opening port 23d. Further, for
example, the flow passage 23A may be formed as a through groove shaped to branch regions
for connecting both the ends of the straight-line part 23c respectively to the end
portion 23a and the end portion 23b. When the branching flow passage 12b branches
the refrigerant flowing therein into two flows, but does not further branch the branched
refrigerant into a plurality of flows, the uniformity in distribution of the refrigerant
can be improved. The regions for connecting both the ends of the straight-line part
23c respectively to the end portion 23a and the end portion 23b may each be a straight
line or a curved line.
[0036] The respective plate-shaped members are stacked by brazing. A both-side clad member
having a brazing material rolled on both surfaces thereof may be used for all of the
plate-shaped members or alternate plate-shaped members to supply the brazing material
for joining. A one-side clad member having a brazing material rolled on one surface
thereof may be used for all of the plate-shaped members to supply the brazing material
for joining. A brazing-material sheet may be stacked between the respective plate-shaped
members to supply the brazing material. A paste brazing material may be applied between
the respective plate-shaped members to supply the brazing material. A both-side clad
member having a brazing material rolled on both surfaces thereof may be stacked between
the respective plate-shaped members to supply the brazing material.
[0037] Through lamination with use of brazing, the plate-shaped members are stacked without
a gap therebetween, which suppresses leakage of the refrigerant and further secures
the pressure resistance. When the plate-shaped members are pressurized during brazing,
the occurrence of brazing failure is further suppressed. When processing that promotes
formation of a fillet, such as forming a rib at a position at which leakage of the
refrigerant is liable to occur, is performed, the occurrence of brazing failure is
further suppressed.
[0038] Further, when all of the members to be subjected to brazing, including the first
heat transfer tube 3 and the fin 5, are made of the same material (for example, made
of aluminum), the members may be collectively subjected to brazing, which improves
the productivity. After the brazing in the stacking-type header 2 is performed, the
brazing of the first heat transfer tube 3 and the fin 5 may be performed. Further,
only the first plate-shaped unit 11 may be first joined to the retaining member 4
by brazing, and the second plate-shaped unit 12 may be joined by brazing thereafter.
[0039] In particular, a plate-shaped member having a brazing material rolled on both surfaces
thereof, in other words, a both-side clad member may be stacked between the respective
plate-shaped members to supply the brazing material. As illustrated in Fig. 2, a plurality
of both-side clad members 24_1 to 24_5 are stacked between the respective plate-shaped
members. In the following, in some cases, the plurality of both-side clad members
24_1 to 24_5 are collectively referred to as the both-side clad member 24.
[0040] The both-side clad member 24 has a flow passage 24A and a flow passage 24B formed
therein, which pass through the both-side clad member 24. When the flow passage 24A
and the flow passage 24B are formed by press working or other processing, the work
is simplified, and the manufacturing cost and the like are reduced. When all of the
members to be subjected to brazing, including the both-side clad member 24, are made
of the same material (for example, made of aluminum), the members may be collectively
subjected to brazing, which improves the productivity.
[0041] The flow passage 24A formed in the both-side clad member 24 stacked on each of the
second plate-shaped member 22 and the third plate-shaped member 23 is a circular through
hole. The flow passage 24B formed in the both-side clad member 24 stacked on each
of the third plate-shaped members 23_1 and 23_2 is a rectangular through hole passing
through substantially the entire region in the height direction of the both-side clad
member 24. The flow passage 24B may not have a rectangular shape. The plurality of
flow passages 24B formed in the both-side clad member 24_4 stacked between the third
plate-shaped member 23_3 and the first plate-shaped member 21 are each a rectangular
through hole. The plurality of flow passages 24B may not each have a rectangular shape.
[0042] The plurality of flow passages 24A and the plurality of flow passages 24B formed
in the both-side clad member 24_5 stacked between the first plate-shaped member 21
and the retaining member 4 are each a through hole having an inner peripheral surface
shaped conforming to the outer peripheral surface of the first heat transfer tube
3.
[0043] When the both-side clad member 24 is stacked, the flow passage 24A functions as a
refrigerant partitioning flow passage for the first outlet flow passage 11A, the distribution
flow passage 12B, and the second inlet flow passage 12A, whereas the flow passage
24B functions as a refrigerant partitioning flow passage for the first inlet flow
passage 11 B, the joining flow passage 12C, and the second outlet flow passage 12D.
Through formation of the refrigerant partitioning flow passage by the both-side clad
member 24, the flows of refrigerant can be reliably partitioned from each other. Further,
when the flows of the refrigerant can be reliably partitioned from each other, the
degree of freedom in design of the flow passage can be increased. Note that, the both-side
clad member 24 may be stacked between a part of the plate-shaped members, and a brazing
material may be supplied between the remaining plate-shaped members by other methods.
[0044] End portions of the first heat transfer tube 3 are projected from a surface of the
retaining member 4. When the both-side clad member 24_5 is stacked on the retaining
member 4 so that the inner peripheral surfaces of the flow passages 24A and 24B of
the both-side clad member 24_5 are fitted to the outer peripheral surfaces of the
respective end portions of the first heat transfer tube 3, the first heat transfer
tube 3 is connected to each of the first outlet flow passage 11 A and the first inlet
flow passage 11 B. The first heat transfer tube 3 and each of the first outlet flow
passage 11 A and the first inlet flow passage 11 B may be positioned through, for
example, fitting between a convex portion formed in the retaining member 4 and a concave
portion formed in the first plate-shaped unit 11. In such a case, the end portions
of the first heat transfer tube 3 may not be projected from the surface of the retaining
member 4. The retaining member 4 may be omitted so that the first heat transfer tube
3 is directly connected to each of the first outlet flow passage 11A and the first
inlet flow passage 11 B. In such a case, the component cost and the like are reduced.
[0045] As illustrated in Fig. 3, the first heat insulating slit 31 is formed between the
flow passage 23A and the flow passage 23B of the third plate-shaped member 23. The
first heat insulating slit 31 may pass through the third plate-shaped member 23 or
may be a bottomed concave portion that does not pass through the third plate-shaped
member 23. The first heat insulating slit 31 may be formed in one row or in a plurality
of rows. The first heat insulating slit 31 may be a straight line or a curved line.
The first heat insulating slit 31 may be a plurality of hole portions formed intermittently.
The hole portions each have a circular shape or an elongated hole shape, for example.
A heat insulating material may be charged in the first heat insulating slit 31. When
the first heat insulating slit 31 passes through the third plate-shaped member 23
and is formed by press working or other processing, the work is simplified, and the
manufacturing cost is reduced. Further, the heat exchange between the refrigerant
passing through the flow passage 23A and the refrigerant passing through the flow
passage 23B can be reliably suppressed.
[0046] The first heat insulating slit 31 may be formed in a different plate-shaped member
or the both-side clad member 24 in a region between the flow passage through which
the refrigerant passes to flow into the first inlet flow passage 11 B and the flow
passage through which the refrigerant passes to flow into the second inlet flow passage
12A. In other words, the first heat insulating slit 31 may be formed in the first
plate-shaped member 21 in a region between the flow passage 21 B and the flow passage
21A. Further, the first heat insulating slit 31 may be formed in the second plate-shaped
member 22 in a region between the flow passage 22B and the flow passage 22A. Further,
the first heat insulating slit 31 may be formed in the both-side clad member 24 in
a region between the flow passage 24B and the flow passage 24A.
<Flow of Refrigerant in Laminated Header>
[0047] Now, the flow of the refrigerant in the stacking-type header of the heat exchanger
according to Embodiment 1 is described.
[0048] As illustrated in Fig. 2 and Fig. 3, the refrigerant passing through the flow passage
22A of the second plate-shaped member 22 flows into the opening port 23d of the flow
passage 23A formed in the third plate-shaped member 23_1. The refrigerant flowing
into the opening port 23d hits against the surface of the member stacked adjacent
to the third plate-shaped member 23_1, and is branched into two flows respectively
toward both the ends of the straight-line part 23c. The branched refrigerant reaches
each of the end portions 23a and 23b of the flow passage 23A, and flows into the opening
port 23d of the flow passage 23A formed in the third plate-shaped member 23_2.
[0049] Similarly, the refrigerant flowing into the opening port 23d of the flow passage
23A formed in the third plate-shaped member 23_2 hits against the surface of the member
stacked adjacent to the third plate-shaped member 23_2, and is branched into two flows
respectively toward both the ends of the straight-line part 23c. The branched refrigerant
reaches each of the end portions 23a and 23b of the flow passage 23A, and flows into
the opening port 23d of the flow passage 23A formed in the third plate-shaped member
23_3.
[0050] Similarly, the refrigerant flowing into the opening port 23d of the flow passage
23A formed in the third plate-shaped member 23_3 hits against the surface of the member
stacked adjacent to the third plate-shaped member 23_3, and is branched into two flows
respectively toward both the ends of the straight-line part 23c. The branched refrigerant
reaches each of the end portions 23a and 23b of the flow passage 23A, and passes through
the flow passage 21 A of the first plate-shaped member 21 to flow into the first heat
transfer tube 3.
[0051] The refrigerant flowing out from the flow passage 21 A of the first plate-shaped
member 21 to pass through the first heat transfer tube 3 flows into the flow passage
21 B of the first plate-shaped member 21. The refrigerant flowing into the flow passage
21 B of the first plate-shaped member 21 flows into the flow passage 23B formed in
the third plate-shaped member 23 to be mixed. The mixed refrigerant passes through
the flow passage 22B of the second plate-shaped member 22 to flow out therefrom toward
the refrigerant pipe.
<Usage Mode of Heat Exchanger>
[0052] Now, an example of a usage mode of the heat exchanger according to Embodiment 1 is
described.
[0053] Note that, in the following, there is described a case where the heat exchanger according
to Embodiment 1 is used for an air-conditioning apparatus, but the present invention
is not limited to such a case, and for example, the heat exchanger according to Embodiment
1 may be used for other refrigeration cycle apparatus including a refrigerant circuit.
Further, there is described a case where the air-conditioning apparatus switches between
a cooling operation and a heating operation, but the present invention is not limited
to such a case, and the air-conditioning apparatus may perform only the cooling operation
or the heating operation.
[0054] Fig. 4 is a view illustrating the configuration of the air-conditioning apparatus
to which the heat exchanger according to Embodiment 1 is applied. Note that, in Fig.
4, the flow of the refrigerant during the cooling operation is indicated by the solid
arrow, while the flow of the refrigerant during the heating operation is indicated
by the dotted arrow.
[0055] As illustrated in Fig. 4, an air-conditioning apparatus 51 includes a compressor
52, a four-way valve 53, a heat source-side heat exchanger 54, an expansion device
55, a load-side heat exchanger 56, a heat source-side fan 57, a load-side fan 58,
and a controller 59. The compressor 52, the four-way valve 53, the heat source-side
heat exchanger 54, the expansion device 55, and the load-side heat exchanger 56 are
connected by refrigerant pipes to form a refrigerant circuit.
[0056] The controller 59 is connected to, for example, the compressor 52, the four-way valve
53, the expansion device 55, the heat source-side fan 57, the load-side fan 58, and
various sensors. The controller 59 switches the flow passage of the four-way valve
53 to switch between the cooling operation and the heating operation. The heat source-side
heat exchanger 54 acts as a condensor during the cooling operation, and acts as an
evaporator during the heating operation. The load-side heat exchanger 56 acts as the
evaporator during the cooling operation, and acts as the condensor during the heating
operation.
[0057] The flow of the refrigerant during the cooling operation is described.
[0058] The refrigerant in a high-pressure and high-temperature gas state discharged from
the compressor 52 passes through the four-way valve 53 to flow into the heat source-side
heat exchanger 54, and is condensed through heat exchange with the outside air supplied
by the heat source-side fan 57, to thereby become the refrigerant in a high-pressure
liquid state, which flows out from the heat source-side heat exchanger 54. The refrigerant
in the high-pressure liquid state flowing out from the heat source-side heat exchanger
54 flows into the expansion device 55 to become the refrigerant in a low-pressure
two-phase gas-liquid state. The refrigerant in the low-pressure two-phase gas-liquid
state flowing out from the expansion device 55 flows into the load-side heat exchanger
56 to be evaporated through heat exchange with indoor air supplied by the load-side
fan 58, to thereby become the refrigerant in a low-pressure gas state, which flows
out from the load-side heat exchanger 56. The refrigerant in the low-pressure gas
state flowing out from the load-side heat exchanger 56 passes through the four-way
valve 53 to be sucked into the compressor 52.
[0059] The flow of the refrigerant during the heating operation is described.
[0060] The refrigerant in a high-pressure and high-temperature gas state discharged from
the compressor 52 passes through the four-way valve 53 to flow into the load-side
heat exchanger 56, and is condensed through heat exchange with the indoor air supplied
by the load-side fan 58, to thereby become the refrigerant in a high-pressure liquid
state, which flows out from the load-side heat exchanger 56. The refrigerant in the
high-pressure liquid state flowing out from the load-side heat exchanger 56 flows
into the expansion device 55 to become the refrigerant in a low-pressure two-phase
gas-liquid state. The refrigerant in the low-pressure two-phase gas-liquid state flowing
out from the expansion device 55 flows into the heat source-side heat exchanger 54
to be evaporated through heat exchange with the outside air supplied by the heat source-side
fan 57, to thereby become the refrigerant in a low-pressure gas state, which flows
out from the heat source-side heat exchanger 54. The refrigerant in the low-pressure
gas state flowing out from the heat source-side heat exchanger 54 passes through the
four-way valve 53 to be sucked into the compressor 52.
[0061] The heat exchanger 1 is used for at least one of the heat source-side heat exchanger
54 or the load-side heat exchanger 56. When the heat exchanger 1 acts as the evaporator,
the heat exchanger 1 is connected so that the refrigerant passes through the distrubution
flow passage 12B of the stacking-type header 2 to flow into the first heat transfer
tube 3, and the refrigerant passes through the first heat transfer tube 3 to flow
into the joining flow passages 12C of the stacking-type header 2. In other words,
when the heat exchanger 1 acts as the evaporator, the refrigerant in the two-phase
gas-liquid state passes through the refrigerant pipe to flow into the distribution
flow passage 12B of the stacking-type header 2, and the refrigerant in the gas state
passes through the first heat transfer tube 3 to flow into the joining flow passages
12C of the stacking-type header 2. Further, when the heat exchanger 1 acts as the
condensor, the refrigerant in the gas state passes through the refrigerant pipe to
flow into the joining flow passages 12C of the stacking-type header 2, and the refrigerant
in the liquid state passes through the first heat transfer tube 3 to flow into the
distribution flow passage 12B of the stacking-type header 2.
<Action of Heat Exchanger>
[0062] Now, an action of the heat exchanger according to Embodiment 1 is described.
[0063] In the stacking-type header 2, the first heat insulating slit 31 is formed in the
plate-shaped member or the both-side clad member 24 in a region between the flow passage
through which the refrigerant passes to flow into the first inlet flow passage 11
B and the flow passage through which the refrigerant passes to flow into the second
inlet flow passage 12A. Therefore, in the stacking-type header 2, the heat exchange
between the refrigerant flowing into the first inlet flow passage 11 B and the refrigerant
flowing into the second inlet flow passage 12A is suppressed.
[0064] Further, the flow passage through which the refrigerant passes to flow into the first
inlet flow passage 11 B is required to have a large flow passage area in order to
reduce the pressure loss caused when the refrigerant in a gas state flows into the
flow passage. When the first heat insulating slit 31 is formed as in the stacking-type
header 2, the heat exchange between the refrigerant flowing into the first inlet flow
passage 11 B and the refrigerant flowing into the second inlet flow passage 12A is
suppressed, and accordingly, it is possible to reduce the interval between the flow
passage through which the refrigerant passes to flow into the first inlet flow passage
11 B and the flow passage through which the refrigerant passes to flow into the second
inlet flow passage 12A so that the flow passage through which the refrigerant passes
to flow into the first inlet flow passage 11 B can have a large flow passage area,
which improves the performance of the stacking-type header 2.
[0065] Further, in the stacking-type header 2, the first heat insulating slit 31 is formed
in the third plate-shaped member 23 in a region between the flow passage 23A and the
flow passage 23B. When the flow passage 23A of the third plate-shaped member 23 includes
the straight-line part 23c perpendicular to the gravity direction, and causes the
refrigerant to flow into a part between both the ends of the straight-line part 23c
to be branched, the straight-line part 23c is required to have a large length in order
to improve the uniformity in branching. When the first heat insulating slit 31 is
formed between the flow passage 23A and the flow passage 23B as in the stacking-type
header 2, the heat exchange between the refrigerant flowing into the first inlet flow
passage 11 B and the refrigerant flowing into the second inlet flow passage 12A is
suppressed, and accordingly, it is possible to reduce the interval between the flow
passage 23A and the flow passage 23B so that the straight-line part 23c of the flow
passage 23A of the third plate-shaped member 23 can have a large length, which improves
the uniformity in distribution of the refrigerant in the stacking-type header 2.
[0066] In particular, even when the stacking-type header 2 is used under a state in which
the superheated refrigerant in a gas state passes through the first heat transfer
tube 3 to flow into the first inlet flow passage 11 B and the refrigerant in a low-temperature
two-phase gas-liquid state passes through the refrigerant pipe to flow into the second
inlet flow passage 12A, in the stacking-type header 2, the heat exchange between the
refrigerant flowing into the first inlet flow passage 11 B and the refrigerant flowing
into the second inlet flow passage 12A is suppressed.
[0067] In particular, in a case where the heat exchanger 1 is used as the heat source-side
heat exchanger 54 or the load-side heat exchanger 56 of the air-conditioning apparatus
51, and, when the heat exchanger 1 acts as the evaporator, the heat exchanger 1 is
connected so that the distribution flow passage 12B causes the refrigerant to flow
out from the first outlet flow passage 11 A, when the heat exchanger 1 acts as the
evaporator, in the stacking-type header 2, the heat exchange between the superheated
refrigerant in a gas state flowing into the first inlet flow passage 11 B and the
refrigerant in a low-temperature two-phase gas-liquid state flowing into the second
inlet flow passage 12A is suppressed. Further, when the heat exchanger 1 acts as the
condensor, in the stacking-type header 2, the heat exchange between the refrigerant
in a high-temperature gas state flowing into the second outlet flow passage 12D and
the subcooled refrigerant in a liquid state flowing into the first outlet flow passage
11A is suppressed. Thus, the heat exchange performance of the heat exchanger 1 is
improved so that the air-conditioning apparatus 51 has higher performance, for example.
[0068] In particular, in the related-art stacking-type header, when the heat transfer tube
is changed from a circular tube to a flat tube for the purpose of reducing the refrigerant
amount or achieving space saving in the heat exchanger, the stacking-type header is
required to be upsized in the entire peripheral direction perpendicular to the refrigerant
inflow direction. On the other hand, the stacking-type header 2 is not required to
be upsized in the entire peripheral direction perpendicular to the refrigerant inflow
direction, and thus space saving is achieved in the heat exchanger 1. In other words,
in the related-art stacking-type header, when the heat transfer tube is changed from
a circular tube to a flat tube, the sectional area of the flow passage in the heat
transfer tube is reduced, and thus the pressure loss caused in the heat transfer tube
is increased. Therefore, it is necessary to further reduce the angular interval between
the plurality of grooves forming the branching flow passage to increase the number
of paths (in other words, the number of heat transfer tubes), which causes upsize
of the stacking-type header in the entire peripheral direction perpendicular to the
refrigerant inflow direction. On the other hand, in the stacking-type header 2, even
when the number of paths is required to be increased, the number of the third plate-shaped
members 23 is only required to be increased, and hence the upsize of the stacking-type
header 2 in the entire peripheral direction perpendicular to the refrigerant inflow
direction is suppressed. Note that, the stacking-type header 2 is not limited to the
case where the first heat transfer tube 3 is a flat tube.
< Modified Example-1>
[0069] Fig. 5 is a view illustrating first heat insulating slits formed in the third plate-shaped
member of Modified Example-1 of the heat exchanger according to Embodiment 1.
[0070] As illustrated in Fig. 5, the first heat insulating slit 31 formed in the third plate-shaped
member 23 in a region between the flow passage 23A and the flow passage 23B may be
formed only in a part of a region between the flow passage 23A and the flow passage
23B. In such a case, it is preferred that the first heat insulating slit 31 be formed
only in a region where a periphery of the flow passage 23A and a periphery of the
flow passage 23B are close to each other. For example, the first heat insulating slit
31 includes a first heat insulating slit 31 a formed between the flow passage 23B
and the straight-line part 23c, and a first heat insulating slit 31 b formed between
the flow passage 23B and the end portion 23b of the flow passage 23A, which communicates
with the end portion of the straight-line part 23c located farther from the flow passage
23B. It is preferred that the first heat insulating slit 31 a be formed between the
flow passage 23B and a region in the flow passage 23A on the side closer to the straight-line
part 23c between the straight-line part 23c and the end portion 23a communicating
with the end portion of the straight-line part 23c, which is located closer to the
flow passage 23B.
<Modified Example-2>
[0071] Fig. 6 is a perspective view of Modified Example-2 of the heat exchanger according
to Embodiment 1 under a state in which the stacking-type header is disassembled.
[0072] As illustrated in Fig. 6, the second plate-shaped member 22 may have the plurality
of flow passages 22A formed therein, in other words, the second plate-shaped unit
12 may have the plurality of second inlet flow passages 12A formed therein, to thereby
reduce the number of the third plate-shaped members 23. With such a configuration,
the component cost, the weight, and the like can be reduced.
<Modified Example-3>
[0073] Fig. 7 is a perspective view of Modified Example-3 of the heat exchanger according
to Embodiment 1 under a state in which the stacking-type header is disassembled.
[0074] As illustrated in Fig. 7, the second plate-shaped member 22 and the third plate-shaped
member 23 may respectively have the plurality of flow passages 22B and the plurality
of flow passages 23B formed therein. In other words, the joining flow passage 12C
may have the plurality of mixing flow passages 12c. The plurality of flow passages
24B of the both-side clad member 24 stacked between the second plate-shaped member
22 and the third plate-shaped member 23_3 have the same shape as the respective plurality
of flow passages 23B.
<Modified Example-4>
[0075] Figs. 8 are a main-part perspective view and a main-part sectional view of Modified
Example-4 of the heat exchanger according to Embodiment 1 under a state in which the
stacking-type header is disassembled. Note that, Fig. 8(a) is a main-part perspective
view under the state in which the stacking-type header is disassembled, and Fig. 8(b)
is a sectional view of the third plate-shaped member 23 taken along the line A-A of
Fig. 8(a).
[0076] As illustrated in Figs. 8, any one of the flow passages 23A formed in the third plate-shaped
member 23 may be a bottomed groove. In such a case, a circular through hole 23e is
formed at each of the end portion 23a and the end portion 23b of a bottom surface
of the groove of the flow passage 23A. With such a configuration, the both-side clad
member 24 is not required to be stacked between the plate-shaped members in order
to interpose the flow passage 24A functioning as the refrigerant partitioning flow
passage between the branching flow passages 12b, which improves the production efficiency.
Note that, in Figs. 8, there is illustrated a case where the refrigerant outflow side
of the flow passage 23A is the bottom surface, but the refrigerant inflow side of
the flow passage 23A may be the bottom surface. In such a case, a through hole may
be formed in a region corresponding to the opening port 23d.
<Modified Example-5>
[0077] Fig. 9 is a perspective view of Modified Example-5 of the heat exchanger according
to Embodiment 1 under a state in which the stacking-type header is disassembled.
[0078] As illustrated in Fig. 9, the flow passage 22A functioning as the second inlet flow
passage 12A may be formed in a member to be stacked other than the second plate-shaped
member 22, in other words, a different plate-shaped member, the both-side clad member
24, or other members. In such a case, the flow passage 22A may be formed as, for example,
a through hole passing through the different plate-shaped member from the side surface
thereof to the surface on the side on which the second plate-shaped member 22 is present.
<Modified Example-6>
[0079] Fig. 10 is a perspective view of Modified Example-6 of the heat exchanger according
to Embodiment 1 under a state in which the stacking-type header is disassembled.
[0080] As illustrated in Fig. 10, the flow passage 22B functioning as the second outlet
flow passage 12D may be formed in a different plate-shaped member other than the second
plate-shaped member 22 of the second plate-shaped unit 12 or the both-side clad member
24. In such a case, for example, a notch may be formed, which communicates between
a part of the flow passage 23B or the flow passage 24B and a side surface of the third
plate-shaped member 23 or the both-side clad member 24. The mixing flow passage 12c
may be turned back so that the flow passage 22B functioning as the second outlet flow
passage 12D is formed in the first plate-shaped member 21.
Embodiment 2
[0081] A heat exchanger according to Embodiment 2 is described.
[0082] Note that, overlapping description or similar description to that of Embodiment 1
is appropriately simplified or omitted.
<Configuration of Heat Exchanger>
[0083] Now, the configuration of the heat exchanger according to Embodiment 2 is described.
[0084] Fig. 11 is a view illustrating the configuration of the heat exchanger according
to Embodiment 2.
[0085] As illustrated in Fig. 11, the heat exchanger 1 includes the stacking-type header
2, the plurality of first heat transfer tubes 3, a plurality of second heat transfer
tubes 6, the retaining member 4, and the plurality of fins 5.
[0086] The stacking-type header 2 includes a plurality of refrigerant turn-back ports 2E.
Similarly to the first heat transfer tube 3, the second heat transfer tube 6 is a
flat tube subjected to hair-pin bending. The plurality of first heat transfer tubes
3 are connected between the plurality of refrigerant outflow ports 2B and the plurality
of refrigerant turn-back ports 2E of the stacking-type header 2, and the plurality
of second heat transfer tubes 6 are connected between the plurality of refrigerant
turn-back ports 2E and the plurality of refrigerant inflow ports 2C of the stacking-type
header 2.
<Flow of Refrigerant in Heat Exchanger>
[0087] Now, the flow of the refrigerant in the heat exchanger according to Embodiment 2
is described.
[0088] The refrigerant flowing through the refrigerant pipe passes through the refrigerant
inflow port 2A to flow into the stacking-type header 2 to be distributed, and then
passes through the plurality of refrigerant outflow ports 2B to flow out toward the
plurality of first heat transfer tubes 3. In the plurality of first heat transfer
tubes 3, the refrigerant exchanges heat with air supplied by a fan, for example. The
refrigerant passing through the plurality of first heat transfer tubes 3 flows into
the plurality of refrigerant turn-back ports 2E of the stacking-type header 2 to be
turned back, and flows out therefrom toward the plurality of second heat transfer
tubes 6. In the plurality of second heat transfer tubes 6, the refrigerant exchanges
heat with air supplied by a fan, for example. The flows of the refrigerant passing
through the plurality of second heat transfer tubes 6 pass through the plurality of
refrigerant inflow ports 2C to flow into the stacking-type header 2 to be joined,
and the joined refrigerant passes through the refrigerant outflow port 2D to flow
out therefrom toward the refrigerant pipe. The refrigerant can reversely flow.
<Configuration of Laminated Header>
[0089] Now, the configuration of the stacking-type header of the heat exchanger according
to Embodiment 2 is described.
[0090] Fig. 12 is a perspective view of the heat exchanger according to Embodiment 2 under
a state in which the stacking-type header is disassembled. Figs. 13 are a developed
view of the stacking-type header of the heat exchanger according to Embodiment 2.
Note that, in Fig. 12, the illustration of each of the first heat insulating slit
31 and a second heat insulating slit 32 is omitted. In Figs. 13, the illustration
of the both-side clad member 24 is omitted. Fig. 13(b) is a view illustrating details
of the portion A of Fig. 13(a), in which the first heat transfer tube 3 and the second
heat transfer tube 6 connected to the respective flow passages are represented by
the dotted lines.
[0091] As illustrated in Fig. 12 and Figs. 13, the stacking-type header 2 includes the first
plate-shaped unit 11 and the second plate-shaped unit 12. The first plate-shaped unit
11 and the second plate-shaped unit 12 are stacked on each other.
[0092] The first plate-shaped unit 11 has the plurality of first outlet flow passages 11
A, the plurality of first inlet flow passages 11 B, and a plurality of turn-back flow
passages 11C formed therein. The plurality of turn-back flow passages 11C correspond
to the plurality of refrigerant turn-back ports 2E in Fig. 11.
[0093] The first plate-shaped member 21 has a plurality of flow passages 21C formed therein.
The plurality of flow passages 21C are each a through hole having an inner peripheral
surface shaped to surround the outer peripheral surface of the end portion of the
first heat transfer tube 3 on the refrigerant outflow side and the outer peripheral
surface of the end portion of the second heat transfer tube 6 on the refrigerant inflow
side. When the first plate-shaped member 21 is stacked, the plurality of flow passages
21C function as the plurality of turn-back flow passages 11C.
[0094] In particular, it is preferred to stack the both-side clad member 24 having a brazing
material rolled on both surfaces thereof between the respective plate-shaped members
to supply the brazing material. The flow passage 24C formed in the both-side clad
member 24_5 stacked between the retaining member 4 and the first plate-shaped member
21 is a through hole having an inner peripheral surface shaped to surround the outer
peripheral surface of the end portion of the first heat transfer tube 3 on the refrigerant
outflow side and the outer peripheral surface of the end portion of the second heat
transfer tube 6 on the refrigerant inflow side. When the both-side clad member 24
is stacked, the flow passage 24C functions as the refrigerant partitioning flow passage
for the turn-back flow passage 11C.
[0095] As illustrated in Fig. 13(b), the second heat insulating slit 32 similar to the first
heat insulating slit 31 is formed in the first plate-shaped member 21 in a region
between the flow passage 21 B and the flow passage 21C. The second heat insulating
slit 32 may be formed in the both-side clad member 24_5 stacked between the retaining
member 4 and the first plate-shaped member 21 in a region between the flow passage
24B and the flow passage 24C. It is only required that the second heat insulating
slit 32 be formed in the plate-shaped member or the both-side clad member 24 in a
region between the flow passage through which the refrigerant passes to flow into
the first inlet flow passage 11 B and the flow passage through which the refrigerant
passes to flow into the turn-back flow passage 11C.
<Flow of Refrigerant in Laminated Header>
[0096] Now, the flow of the refrigerant in the stacking-type header of the heat exchanger
according to Embodiment 2 is described.
[0097] As illustrated in Fig. 12 and Figs. 13, the refrigerant flowing out from the flow
passage 21 A of the first plate-shaped member 21 to pass through the first heat transfer
tube 3 flows into the flow passage 21C of the first plate-shaped member 21 to be turned
back and flow into the second heat transfer tube 6. The refrigerant passing through
the second heat transfer tube 6 flows into the flow passage 21 B of the first plate-shaped
member 21. The refrigerant flowing into the flow passage 21 B of the first plate-shaped
member 21 flows into the flow passage 23B formed in the third plate-shaped member
23 to be mixed. The mixed refrigerant passes through the flow passage 22B of the second
plate-shaped member 22 to flow out therefrom toward the refrigerant pipe.
<Usage Mode of Heat Exchanger>
[0098] Now, an example of a usage mode of the heat exchanger according to Embodiment 2 is
described.
[0099] Fig. 14 is a diagram illustrating a configuration of an air-conditioning apparatus
to which the heat exchanger according to Embodiment 2 is applied.
[0100] As illustrated in Fig. 14, the heat exchanger 1 is used for at least one of the heat
source-side heat exchanger 54 or the load-side heat exchanger 56. When the heat exchanger
1 acts as the evaporator, the heat exchanger 1 is connected so that the refrigerant
passes through the distribution flow passage 12B of the stacking-type header 2 to
flow into the first heat transfer tube 3, and the refrigerant passes through the second
heat transfer tube 6 to flow into the joining flow passage 12C of the stacking-type
header 2. In other words, when the heat exchanger 1 acts as the evaporator, the refrigerant
in a two-phase gas-liquid state passes through the refrigerant pipe to flow into the
distribution flow passage 12B of the stacking-type header 2, and the refrigerant in
a gas state passes through the second heat transfer tube 6 to flow into the joining
flow passage 12C of the stacking-type header 2. Further, when the heat exchanger 1
acts as the condensor, the refrigerant in a gas state passes through the refrigerant
pipe to flow into the joining flow passage 12C of the stacking-type header 2, and
the refrigerant in a liquid state passes through the first heat transfer tube 3 to
flow into the distribution flow passage 12B of the stacking-type header 2.
[0101] Further, when the heat exchanger 1 acts as the condensor, the heat exchanger 1 is
arranged so that the first heat transfer tube 3 is positioned on the upstream side
(windward side) of the air stream generated by the heat source-side fan 57 or the
load-side fan 58 with respect to the second heat transfer tube 6. In other words,
there is obtained a relationship that the flow of the refrigerant from the second
heat transfer tube 6 to the first heat transfer tube 3 and the air stream are opposed
to each other. The refrigerant of the first heat transfer tube 3 is lower in temperature
than the refrigerant of the second heat transfer tube 6. The air stream generated
by the heat source-side fan 57 or the load-side fan 58 is lower in temperature on
the upstream side of the heat exchanger 1 than on the downstream side of the heat
exchanger 1. As a result, in particular, the refrigerant can be subcooled (so-called
subcooling) by the low-temperature air stream flowing on the upstream side of the
heat exchanger 1, which improves the condensor performance. Note that, the heat source-side
fan 57 and the load-side fan 58 may be arranged on the windward side or the leeward
side.
[0102] <Action of Heat Exchanger>
[0103] Now, the action of the heat exchanger according to Embodiment 2 is described.
[0104] In the heat exchanger 1, the first plate-shaped unit 11 has the plurality of turn-back
flow passages 11C formed therein, and in addition to the plurality of first heat transfer
tubes 3, the plurality of second heat transfer tubes 6 are connected. For example,
it is possible to increase the area in a state of the front view of the heat exchanger
1 to increase the heat exchange amount, but in this case, the housing that incorporates
the heat exchanger 1 is upsized. Further, it is possible to decrease the interval
between the fins 5 to increase the number of the fins 5, to thereby increase the heat
exchange amount. In this case, however, from the viewpoint of drainage performance,
frost formation performance, and anti-dust performance, it is difficult to decrease
the interval between the fins 5 to less than about 1 mm, and thus the increase in
heat exchange amount may be insufficient. On the other hand, when the number of rows
of the heat transfer tubes is increased as in the heat exchanger 1, the heat exchange
amount can be increased without changing the area in the state of the front view of
the heat exchanger 1, the interval between the fins 5, or other matters. When the
number of rows of the heat transfer tubes is two, the heat exchange amount is increased
about 1.5 times or more. Note that, the number of rows of the heat transfer tubes
may be three or more. Still further, the area in the state of the front view of the
heat exchanger 1, the interval between the fins 5, or other matters may be changed.
[0105] Further, the header (stacking-type header 2) is arranged only on one side of the
heat exchanger 1. For example, when the heat exchanger 1 is arranged in a bent state
along a plurality of side surfaces of the housing incorporating the heat exchanger
1 in order to increase the mounting volume of the heat exchanging unit, the end portion
may be misaligned in each row of the heat transfer tubes because the curvature radius
of the bent part differs depending on each row of the heat transfer tubes. When, as
in the stacking-type header 2, the header (stacking-type header 2) is arranged only
on one side of the heat exchanger 1, even when the end portion is misaligned in each
row of the heat transfer tubes, only the end portions on one side are required to
be aligned, which improves the degree of freedom in design, the production efficiency,
and other matters. In particular, the heat exchanger 1 can be bent after the respective
members of the heat exchanger 1 are joined to each other, which further improves the
production efficiency.
[0106] Further, when the heat exchanger 1 acts as the condensor, the first heat transfer
tube 3 is positioned on the windward side with respect to the second heat transfer
tube 6. When the headers are arranged on both sides of the heat exchanger, it is difficult
to provide a temperature difference in the refrigerant for each row of the heat transfer
tubes to improve the condensor performance. In particular, when the first heat transfer
tube 3 and the second heat transfer tube 6 are flat tubes, unlike a circular tube,
the degree of freedom in bending is low, and hence it is difficult to realize providing
the temperature difference in the refrigerant for each row of the heat transfer tubes
by deforming the flow passage of the refrigerant. On the other hand, when the first
heat transfer tube 3 and the second heat transfer tube 6 are connected to the stacking-type
header 2 as in the heat exchanger 1, the temperature difference in the refrigerant
is inevitably generated for each row of the heat transfer tubes, and obtaining the
relationship that the refrigerant flow and the air stream are opposed to each other
can be easily realized without deforming the flow passage of the refrigerant.
[0107] Further, in the stacking-type header 2, the second heat insulating slit 32 similar
to the first heat insulating slit 31 is formed in the plate-shaped member or the both-side
clad member 24 in a region between the flow passage through which the refrigerant
passes to flow into the first inlet flow passage 11 B and the flow passage through
which the refrigerant passes to flow into the turn-back flow passage 11C. Therefore,
in the stacking-type header 2, the heat exchange between the refrigerant flowing into
the first inlet flow passage 11 B and the refrigerant flowing into the turn-back flow
passage 11C is suppressed.
[0108] Further, the flow passage through which the refrigerant passes to flow into the first
inlet flow passage 11 B is required to have a large flow passage area in order to
reduce the pressure loss caused when the refrigerant in a gas state flows into the
flow passage. When the second heat insulating slit 32 is formed between the flow passage
21 B and the flow passage 21C as in the stacking-type header 2, the heat exchange
between the refrigerant flowing into the first inlet flow passage 11 B and the refrigerant
flowing into the turn-back flow passage 11C is suppressed, and accordingly, it is
possible to reduce the interval between the first inlet flow passage 11 B and the
turn-back flow passage 11C so that the first inlet flow passage 11 B can have a large
flow passage area, which improves the performance of the stacking-type header 2.
[0109] In particular, when a starting point of the array of the first heat transfer tubes
3 and a starting point of the array of the second heat transfer tubes 6 are misaligned,
as illustrated in Fig. 13(b), the sectional area of the flow passage 21C is increased,
which reduces the interval between the first inlet flow passage 11 B and the turn-back
flow passage 11C. When the second heat insulating slit 32 is formed between the flow
passage 21 B and the flow passage 21C as in the stacking-type header 2, the heat exchange
between the refrigerant flowing into the first inlet flow passage 11 B and the refrigerant
flowing into the turn-back flow passage 11C is suppressed, and accordingly, even when
the sectional area of the flow passage 21C is increased, it is possible to reduce
the interval between the first inlet flow passage 11 B and the turn-back flow passage
11C so that the first inlet flow passage 11 B can have a large flow passage area,
which improves the performance of the stacking-type header 2.
[0110] The present invention has been described above with reference to Embodiment 1 and
Embodiment 2, but the present invention is not limited to those embodiments. For example,
a part or all of the respective embodiments, the respective modified examples, and
the like may be combined.
Reference Signs List
[0111]
1 heat exchanger 2 stacking-type header 2A refrigerant inflow port
2B refrigerant outflow port 2C refrigerant inflow port 2D refrigerant outflow port
2E refrigerant turn-back port 3 first heat transfer tube4 retaining member 5 fin 6
second heat transfer tube 11 first plate-shaped unit
11 A first outlet flow passage 11B first inlet flow passage 11C turn-back flow passage
12 second plate-shaped unit 12A second inlet flow passage
12B distrubution flow passage 12C joining flow passage 12D second outlet flow passage
12b branching flow passage 12c mixing flow passage
21 first plate-shaped member 21A-21C flow passage 22 second plate-shaped member 22A,
22B flow passage 23, 23_1-23_3 third plate-shaped member 23A, 23B, 23A_1-23A_3, 23B_1-23B_3
flow passage 23a, 23b end portion 23c straight-line part 23d opening port 23e through
hole 24, 24_1-24_5 both-side clad member 24A-24C flow passage 31, 31 a, 31 b first
heat insulating slit 32 second heat insulating slit 51 air-conditioning apparatus
52 compressor 53 four-way valve 54 heat source-side heat exchanger 55 expansion device
56 load-side heat exchanger 57 heat source-side fan 58 load-side fan 59 controller